Diffuse idiopathic skeletal hyperostosis (DISH, also known as Forestier's disease and ankylosing hyperostosis) is a non-inflammatory spondyloarthropathy. It is characterized by spiny ankylosis and ossification of spinal ligaments and entheses. Involvement is variable, but can involve the entire spine. The disc spaces and facet joints remain unaffected. Classically, advanced disease may have "melted candle wax" appearance along the spine on radiographic studies.
The exact cause is unknown. Mechanical factors, dietary and long term use of some antidepressants may be of significance. There is a correlation between these factors but not a cause or effect. The distinctive radiological feature of DISH is the continuous linear calcification along the antero-medial aspect of the thoracic spine. The disease is usually found in people in their 60s and above, and is extremely rare in people in their 40s and 30s. The disease can spread to any joint of the body, affecting the neck, shoulders, ribs, hips, pelvis, knees, ankles, and hands. The disease is not fatal, however some associated complications can lead to death. Complications include paralysis, dysphagia (the inability to swallow), and pulmonary infections. Although DISH manifests in a similar manner to ankylosing spondylitis, these two are totally separate diseases. Ankylosing spondylitis is a genetic disease with identifiable marks, and affects organs. DISH has no indication of a genetic link, and does not affect organs other than the lungs, which is only indirect due to the fusion of the rib cage.
DISH may be symptomatic for thoracic spinal pain in approximately 80% of patients. It may also be discovered as an incidental radiological abnormality, as mentioned above, without any symptoms. Back pain or stiffness is worse in the morning in almost two-thirds of patients. Increased incidence of dysphagia is also reported in some cases. Similar calcification and ossification may be seen at peripheral entheseal sites, including the shoulder, iliac crest, ischial tuberosity, trochanters of the hip, tibial tuberosities, patellae, and bones of the hands and/or feet.
Physiotherapy and manipulative therapy done using CD-SSAT at Capri Spine Clinic shows beneficial results for decreasing pain and increasing spinal range of motion for such patients.